The present invention generally pertains to lanyards and shock absorbing lanyards. More specifically, the present invention pertains to shock absorbing lanyards having a shock absorbing member and a load bearing member, wherein the shock absorbing member is substantially shorter than the load bearing member. The relative lengths of the shock absorbing member and the load bearing member are automatically adjusted. Also, the shock absorbing member and the load bearing member may be woven together. The present invention further pertains to methods of making shock absorbing lanyards. The present invention provides improved lanyards which can elongate, absorb energy and support a load.
People who are at elevated positions above a floor or other relatively lower surface can be at risk of falling and injury. For example, workers and other personnel who have occupations which require them to be at elevated positions, such as on scaffolding, can be at risk of falling and injury. Safety harnesses can be worn to stop a person's fall and prevent or reduce injury.
Safety harnesses typically have a harness portion worn by the user and a tether or lanyard extending from the harness portion. The lanyard connects the harness portion to a secure structure. If the person falls from the elevated position, the safety harness stops the person's fall when the lanyard is straightened. The person's fall is stopped rather abruptly and the person is subjected to the shock force of the abrupt stop.
Accordingly, needs exist to improve lanyards which reduce the shock experienced by the users of safety harnesses when a fall is stopped.
Lanyards which attempt to absorb the shock of a person's fall are known. However, needs exist for improved lanyards which reduce the shock of stopping a person's fall. Current lanyards have been made from two separate webbings assembled together. One webbing is a narrow, flat webbing woven of partially oriented yarn (POY webbing) and the other webbing is a relatively higher strength tubular-shaped webbing. After manufacture of the two webbings, the POY webbing is inserted into one end of the tubular-shaped webbing and pulled through the tubular-shaped webbing. A hook or other device inserted into the opposite end of the tubular-shaped webbing can be used to pull the POY webbing through the tubular-shaped webbing. The POY webbing is pulled through the tubular-shaped webbing so that the POY webbing extends inside of the tubular-shaped webbing from one end to the opposite end. The relative lengths of the POY webbing and the tubular-shaped webbing must be adjusted. While holding the POY webbing in place, one end of the tubular-shaped webbing is moved closer to the opposite end to place the tubular-shaped webbing in an accordion-like position over the POY webbing. The relative length adjustment of the webbings is performed manually and is a significant disadvantage of existing lanyards. After the manual adjustment of the relative webbing lengths, the POY webbing is essentially in a straight, linear orientation inside of the accordion-shaped orientation of the tubular-shaped webbing. The two webbings are then attached to each other by sewing at the ends. Any excess POY webbing extending out of the ends of the tubular-shaped webbing is cut off and discarded.
Those existing lanyards exhibit disadvantages and can be improved. For example, the lanyards are made from two separate webbings which must be assembled together. Manufacture of the lanyards requires costly and tedious assembly processes, such as inserting the POY webbing through the tubular-shaped webbing. Also, after the insertion process, an additional process is required to place the tubular-shaped webbing in the accordion position while maintaining the POY webbing in a straight position, i.e., adjust the relative webbing lengths. Furthermore, a manual process is used to adjust the relative webbing lengths. Then, another process must attach the two separate webbings together while maintaining the POY webbing in the straight position and the tubular-shaped webbing in the accordion-shaped position. The relative lengths of the POY webbing and the tubular-shaped webbing is critical for proper functioning of the lanyard. The manufacturing process is complicated by proper control and manual setting of the critical relative lengths of the two webbings.
Existing lanyards which purport to reduce shock can be found in U.S. Pat. Nos. 5,113,981; 6,085,802; 6,390,234; and 6,533,066 and WIPO Publication No. WO/01/026738.
For the reasons mentioned above and for other reasons, lanyards and shock absorbing lanyards can be improved. For example, one improvement would be to provide a shock absorbing lanyard which has a shock absorbing member and a load bearing web in which the relative lengths of the webs are automatically adjusted. Furthermore, methods of making lanyards can also be improved. One improved method of making a lanyard, for example, would be to adjust the relative lengths of a shock absorbing member and a load bearing web by shrinking the length of the shock absorbing member.